Joseph Garner, director of "Craigslist Joe," wanted to see whether or not online communities could actually take care of people in real life. Here, Garner talks about how to get just about anything you need from social media—and some IRL chutzpah.

According to a 2010 survey by Pew Research Center, 28% of Americans don’t know any of their neighbors by name, and only 9% communicate with them via email. Those unfriendly statistics are something startup Nextdoor.com hopes to change.